1. Field of the Invention
This invention relates to a high temperature heating vessel and in particular, to a refractory clad, cooled metal lid for a glass melting furnace.
2. Technical Considerations
Advances in glass melting technology have resulted in new furnace designs in which batch material is liquefied in large volumes in a relatively small liquefication vessel, for example as disclosed in U.S. Pat. No. 4,381,934 to Kunkel and Matesa. This type of process, particularly when using intensified heat sources, produces relative small volumes of high temperature exhaust gas. The heat from this exhaust gas may be recovered and used to directly heat a batch stream of material feeding the liquefaction vessel so as to improve the overall efficiency of the process.
In a glass batch melting process as taught in U.S. Pat. No. 4,381,934 the heating process may cause portions of the batch material being heated to vaporize. These vapors are corrosive and combine with high temperature exhaust gas from the heating burners that circulates throughout the vessel to form a high temperature corrosive gas that corrodes exposed inner surfaces of the vessel. The corrosion may be accelerated by the high temperature environment within the heating vessel. Particulate materials entrained in the exhaust gas as a result of the liquefaction process have an abrasive action on the exposed surfaces to further reduce the operating life of such a member.
Due to the corrosive affects of the exhaust gas stream within the vessel which are accelerated by the high temperature, as well as any abrasive or erosive affects of the entrained particulates, exposed surfaces within the vessel must be designed to withstand these deleterious conditions so as to reduce maintenance and/or replacement that is necessitated by excessive wear. Massive cooling of the exposed surface to reduce surface temperature may reduce surface wear, but at the same time it has the undesirable affect of reducing the thermal efficiency of the overall melting system by removing heat from the system.
It would be advantageous to have an insulating, wear resistant surface design that can withstand such operating conditions and provide a prolonged operating life while maintaining the thermal efficiency of the system.